Intel E3815 FH8065301567411 数据表
产品代码
FH8065301567411
Intel
®
Atom™ Processor E3800 Product Family
Datasheet
2497
19.6.37
DB_3—Offset 48Ch
The Doorbell Array is organized as an array of up to 256 Doorbell Registers. One 32-bit
Doorbell Register is defined in the array for each Device Slot. System software utilizes
the Doorbell Register to notify the xHC that it has Device Slot related work for the xHC
to perform.
Access Method
Default: 00000000h
7:0
0h
RW
DB_TARGET:
DB Target RW. Doorbell Target. This field defines the target of the
doorbell reference. The table below defines the xHC notification that is generated by
ringing the doorbell. Note that Doorbell Register 0 is dedicated to Command Ring and
decodes this field differently than the other Doorbell Registers. Device Context Doorbells
(1-255) for Value 0 the Definition is Reserved for Value 1 the Definition is Control EP 0
Enqueue Pointer Update for Value 2 the Definition is EP 1 OUT Enqueue Pointer Update
for Value 3 the Definition is EP 1 IN Enqueue Pointer Update for Value 4 the Definition is
EP 2 OUT Enqueue Pointer Update for Value 5 the Definition is EP 2 IN Enqueue Pointer
Update . . . for Value 30 the Definition is EP 15 OUT Enqueue Pointer Update for Value
31 the Definition is EP 15 IN Enqueue Pointer Update for Value 32:247 the Definition is
Reserved for Value 248:255 the Definition is Vendor Defined Host Controller Doorbell (0)
for Value 0 the Definition is Command Doorbell for Value 1:247 the Definition is
Reserved for Value 248:255 the Definition is Vendor Defined This field returns 0 when
read and should be treated as undefined by software. When the Command Doorbell is
written, the DB Stream ID field shall be cleared to 0.
Bit
Range
Default &
Access
Description
Type:
Memory Mapped I/O Register
(Size: 32 bits)
DB_3:
BAR Type:
PCI Configuration Register (Size: 32 bits)
BAR Reference:
[B:0, D:22, F:0] + 10h
31
28
24
20
16
12
8
4
0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
DB
_
S
TREA
M_ID
RSV
D
33
DB_T
ARGET
Bit
Range
Default &
Access
Description
31:16
0h
RW
DB_STREAM_ID:
DB Stream ID - RW. Doorbell Stream ID. If the endpoint of a Device
Context Doorbell defines Streams, then this field shall be used to identify which Stream
of the endpoint the doorbell reference is targeting. System software is responsible for
ensuring that the value written to this field is valid. If the endpoint defines Streams
(MaxPStreams ) 0), then 0, 65535 (No Stream) and 65534 (Prime) are reserved Stream
ID values and shall not be written to this field. If the endpoint does not define Streams
(MaxPStreams = 0) and a non-'0' value is written to this field, the doorbell reference
shall be ignored. This field only applies to Device Context Doorbells and shall be cleared
to 0 for Host Controller Command Doorbells. This field returns 0 when read.
15:8
0h
RO
RSVD33:
reserved